LOS ANGELES, April 29 (Xinhua) -- The heat shield for the U.S. National Aeronautics and Space Administration (NASA)'s upcoming Mars rover suffered a fracture during testing recently, but the situation will not affect the mission's launch readiness date of July 17, 2020, NASA's Jet Propulsion Laboratory (JPL) said.

The fracture, which occurred near the heat shield's outer edge and spans the circumference of the component, happened during a weeklong test at the Denver facility of contractor Lockheed Martin Space, according to the NASA Mars 2020 Mission Status Report released this week.

The test was intended to subject the heat shield to forces up to 20 percent greater than those it will experience during entry into the Martian atmosphere.

"While the fracture was unexpected, it represents why spaceflight hardware is tested in advance so that design changes or fixes can be implemented prior to launch", JPL said.

NASA officials said the current heat shield will be repaired to support the prelaunch spacecraft testing. A new heat shield structure will be readied for flight over the next year.

The heat shield is part of the thermal protection system and aeroshell designed to encapsulate and protect the Mars 2020 rover and landing system from the intense heat generated during descent into the Martian atmosphere. The structure was originally tested in 2008 and was one of two heat shields manufactured in support of the Mars Science Laboratory mission, which successfully landed the Curiosity rover on Mars in August 2012.

The Mars 2020 mission, which is scheduled to arrive at the Red Planet in early 2021, is designed to search the Red Planet's surface for signs of ancient microbial life, and the six-wheeled robot will also hunt for and characterize potentially habitable environments.